Although variation in practice is ubiquitous, many studies have documented that underserved populations such as racial and ethnic minorities, women and children, those with lower socioeconomic status, and persons with HIV/AIDS are significantly less likely than others to receive care that is consistent with the best health care evidence. The overarching premise of the Reducing Health Disparities Through Informatics (RHeaDI) research training program is that information technology and informatics processes are essential components of an infrastructure to reduce health disparities and to facilitate evidence-based practice in the underserved. In regards to this premise, current research training programs in nursing, nursing informatics, or biomedical informatics typically focus on health disparities and evidence-based practice or on informatics. Columbia University is uniquely positioned to offer interdisciplinary research training for nurses that is focused on the use of informatics (i.e., theories, methods, processes, and tools) to reduce health disparities and facilitate evidence-based practice in underserved populations. The School of Nursing and Department of Biomedical Informatics are internationally recognized for academic excellence. An established informatics infrastructure exists for clinical care, education, and research. Moreover, the School of Nursing and Department of Biomedical Informatics have a documented history of interdisciplinary collaboration and of commitment and service to underserved populations. In this competing continuation request for T32 NR007969, we propose to train nurses in informatics at the predoctoral (n=3) and postdoctoral level (n=1). At the predoctoral level, nurses will be supported to earn either a DNSc with a focus on Nursing Informatics or a PhD in Biomedical Informatics. The epistemological distinction between these two "tracks" is type of knowledge generated by the research. DNSc students will apply existing information technology, methods, and tools to build new nursing knowledge. In contrast, nurses in the PhD program will conduct research in order to develop information science knowledge. Common across both programs is a series of courses on vulnerable populations, theory, research methods, and bioinformatics methods. RHeaDI trainees have demonstrated a high level of scholarly productivity during the initial award period and several have secured interdisciplinary academic positions at the conclusion of their educational programs.